An item was originally priced at $6, but you used a coupon and bought it for $4.80. What percent was the coupon you used?
2 answers:
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Answer:
Step-by-step explanation:
The confidence interval for population mean is given by :-
Given : Sample size : , which is a large sample , so we apply z-test .
Sample mean :
Standard deviation :
Significance level :
Critical value :
Now, a confidence interval at the 95% level of confidence will be :-